On a portable electronic device, the performance of applications that use wireless networks to transfer data is highly dependent on the throughput of the wireless network. The network speeds of older wireless network technologies such as GPRS (General Packet Radio Service), for example, vary significantly from those of more modern wireless networks such as EDGE (Enhanced Data GSM (Global Systems for Mobile) Environment), UMTS (Universal Mobile Telecommunications System) and HSDPA (High Speed Downlink Packet Service), for example.
Typically, the chunk size is a default value that is determined for a specific device type. If the default chunk size is large, devices operating on slower networks will perform poorly. If the default chunk size is small, devices operating on high speed networks will not fully utilize the capability of the network. Therefore, it is desirable to select a chunk size that is suited to the wireless network in order to optimize data transfer.